On Sun, 2017-03-19 at 12:14 +0000, Russell King - ARM Linux wrote:

On Sat, Mar 18, 2017 at 12:58:27PM -0700, Steve Longerbeam wrote:

quoted

On 03/18/2017 12:22 PM, Russell King - ARM Linux wrote:

quoted

0:00:01.955927879 20954  0x15ffe90 INFO                    v4l2 gstv4l2object.c:3811:gst_v4l2_object_get_caps:<v4l2src0> probed caps: video/x-bayer, format=(string)rggb, framerate=(fraction)30000/1001, width=(int)816, height=(int)616, pixel-aspect-ratio=(fraction)1/1; video/x-raw, format=(string)I420, framerate=(fraction)30000/1001, width=(int)816, height=(int)616, interlace-mode=(string)progressive, pixel-aspect-ratio=(fraction)1/1; video/x-raw, format=(string)YV12, framerate=(fraction)30000/1001, width=(int)816, height=(int)616, interlace-mode=(string)progressive, pixel-aspect-ratio=(fraction)1/1; video/x-raw, format=(string)BGR, framerate=(fraction)30000/1001, width=(int)816, height=(int)616, interlace-mode=(string)progressive, pixel-aspect-ratio=(fraction)1/1; video/x-raw, format=

 (string)RGB, framerate=(fraction)30000/1001, width=(int)816, height=(int)616, interlace-mode=(string)progressive, pixel-aspect-ratio=(fraction)1/1

quoted

quoted

   despite the media pipeline actually being configured for 60fps.

   Forcing it by adjusting the pipeline only results in gstreamer
   failing, because it believes that v4l2 is unable to operate at
   60fps.

   Also note the complaints from v4l2src about the non-compliance...

Thanks, I've fixed most of v4l2-compliance issues, but this is not
done yet. Is that something you can help with?

I've looked at this, and IMHO it's yet another media control API mess.

- media-ctl itself allows setting the format on subdev pads via
  struct v4l2_subdev_format.

- struct v4l2_subdev_format contains a struct v4l2_mbus_framefmt.

- struct v4l2_mbus_framefmt contains:
  * @width:      frame width
  * @height:     frame height
  * @code:       data format code (from enum v4l2_mbus_pixelcode)
  * @field:      used interlacing type (from enum v4l2_field)
  * @colorspace: colorspace of the data (from enum v4l2_colorspace)
  * @ycbcr_enc:  YCbCr encoding of the data (from enum v4l2_ycbcr_encoding)
  * @quantization: quantization of the data (from enum v4l2_quantization)
  * @xfer_func:  transfer function of the data (from enum v4l2_xfer_func)

- media-ctl sets width, height, code and field, but nothing else.

We're already agreed that the fields that media-ctl are part of the
format negotiation between the ultimate source, flowing down to the
capture device.  However, there's no support in media-ctl to deal
with these other fields - so media-ctl in itself is only half-
implemented.

To set and read colorimetry information:
https://patchwork.linuxtv.org/patch/39350/

regards
Philipp